Account Calculation; added new script event to Validate/ Update properties

A new "CalculateValidate" scripting event has been added to Account Calculations. This runs at the very beginning of a calculation when the Account is still a quotation.

This can be used for several purposes:

• Validate the calculation properties and stop the calculation
• Update the calculation properties

The script handling this event must be configured on the Account Type, Scripts page. The Script Type is "Object Events", Object "Account".